In the present work all electron ab initio multiconfiguration self-consistent-held (CASSCF) and multireference configuration interaction (MRCI) calculations have been carried out to determine the low-lying electronic states of the molecule MoC. The relativistic corrections for the one electron Darwin contact term and the relativistic mass-velocity correction have been determined in perturbation calculations. The electronic ground state is predicted as (3) Sigma(-). The spectroscopic constants for the (3) Sigma(-) electronic ground state and eight low-lying excited states have been derived by solving the Schrodinger equation for the nuclear motion numerically. Based on the results of the CASSCF calculations the (3) Sigma(-) ground state of MoC is separated from the excited states (3) Delta, (5) Sigma-, (1) Sigma, (1) Delta, (5) Pi, (1) Sigma(+), and (3) Pi by transition energies of 4500, 6178, 7207, 9312, 10 228, 11 639, and 16 864 cm(-1), respectively. The transition energy between the (3) Sigma(-) ground state and the (3) Pi state as derived in the MRCI calculations is 15 484 cm(-1). For the (3) Sigma(-) ground state the equilibrium distance has been determined as 1.688 Angstrom, and the vibrational frequency as 997 cm(-1). The chemical bond in the (3) Sigma(-) electronic ground state has triple bond character due to the formation of delocalized bonding rr and a orbitals. The chemical bond in the MoC molecule is polar with charge transfer from Mo to C, giving rise to a dipole moment of 6.15 D at 3.15 a.u. in the (3) Sigma(-) ground state. (C) 1997 American Institute of Physics.
Bibliographical noteCopyright (1997) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.
Shim, I., & Gingerich, K. A. (1997). Electronic states and nature of bonding in the molecule MoC by all electron ab initio calculations. Journal of Chemical Physics, 106(19), 8093-8100. https://doi.org/10.1063/1.473887